2011～2012北京大气PM_(2.5)中重金属的污染特征与来源分析

Chemical Characteristics and Sources of Heavy Metals in Fine Particles in Beijing in 2011-2012

为研究北京PM_(2.5)中重金属污染特征,于2011年夏季~2012年夏季每3 d采集一次PM_(2.5)样品.利用电感耦合等离子体质谱(ICP-MS)分析了Li、V、Cr、Mn、Co、Cu、Zn、As、Se、Ti、Ga、Ni、Sr、Cd、In、Ba、Tl、Pb、Bi和U的浓度,选取其中Zn、Pb、Mn、Cu、As、V和Cr 7种主要重金属元素进行深入讨论.北京市PM_(2.5)中重金属Zn、Pb、Mn、Cu、As、V和Cr的平均质量浓度分别为(331.30±254.52)、(212.64±182.06)、(85.96±47.00)、(45.19±27.74)、(17.13±19.02)、(4.92±3.38)和(9.04±7.84)ng·m-3.采样期间秋冬季节PM_(2.5)中重金属污染较春夏季节严重,这可能与北京秋冬季节取暖导致煤燃烧增加有关.霾过程会加剧北京PM_(2.5)中主要重金属Zn、Pb、Mn、Cu、As、V和Cr的污染,霾天对重金属污染的增加作用呈现一定的季节变化特征.源分析结果表明北京大气颗粒物中重金属主要来源于扬尘(包括建筑扬尘和道路扬尘)和煤燃烧,少量来自远距离输送和其他工业来源.

In order to investigate the chemical characteristics and sources of atmospheric heavy metals,PM（2.5）samples were collected every three days during the summer of 2011 and summer of 2012. The samples were analyzed for Li,V,Cr,Mn,Co,Cu,Zn,As,Se,Ti,Ga,Ni,Sr,Cd,In,Ba,Tl,Pb,Bi,and U by ICP-MS,with an emphasis on seven major heavy metal elements（ Zn,Pb,Mn,Cu,As,V,and Cr）. The concentrations of Zn,Pb,Mn,Cu,As,V,and Cr were（ 331. 30 ± 254. 52）,（ 212. 64 ± 182. 06）,（ 85. 96 ± 47. 00）,（ 45. 19 ± 27. 74）,（ 17. 13 ± 19. 02）,（ 4. 92 ± 3. 38）,and（ 9. 04 ± 7. 84） ng·m-3in PM（2.5）in Beijing during the summer of 2011 and the summer of 2012. In the autumn and winter seasons,PM（2.5）/heavy metal pollution is more severe than in spring and summer,which may be related to the increase in coal combustion used for heating in autumn and winter in Beijing. Haze pollution enhances the concentrations of seven heavy metals in PM（2.5）in Beijing and the enhancement shows seasonal variations. The source analysis suggested that dust（ including building dust and road dust） and coal combustion might be two most important sources of heavy metals in Beijing,and transport and other industrial sources cannot be ignored.